Biomedical Engineering Reference
In-Depth Information
20. For instance, 21 CFR 820.72(b). See Andrew Lowery
et al.
(1996). According to National Institute of
Standards and Technology (NIST) (2003):
Calibration is a measurement process that assigns
values to the property of an artifact or to the response
of an instrument relative to reference standards or to
a designated measurement process. The purpose of
calibration is to eliminate or reduce bias in the user's
measurement system relative to the reference base.
Available from:
http://www.itl.nist.gov/div898/handbook
21. Lowery et al. (1996) ibid.
22. See NIST (2003) op. cit. The FDA has defi ned accuracy
as “the measure of an instrument's capability to
approach a true or absolute value. Accuracy is a function
of precision and bias.” Bias, in turn, is defi ned as “a
measure of how closely the mean value in a series of
replicate measurements approaches the true value;” see
Lowery et al. (1996) op cit.
23. See International Organization of Legal Metrology
(2004).
24. As FDA has stated, “Calibration standards used for
inspection, measuring, and test equipment shall be
traceable to national or international standards;” see 21
CFR 820.72, “Inspection, measuring, and test
equipment.”
25. Lowery et al. (1996), op cit.
26. Available from:
www.fda.gov/foi/warning_letters/
archive/1857b.pdf
See also FDA Warning Letter to
American Blending and Filling dated 27 September
2001, pointing out the “Failure to establish written
procedures for the calibration of compounding and
laboratory equipment. Instruments utilized in the
